(ITS#4774) Add network timeout option to ldapsearch

Full_Name: Luke Howard
Version: HEAD
OS:
URL: http://www.padl.com/~lukeh/openldap-HEAD-nto.diff
Submission from: (NULL) (203.13.32.80)
A customer had requested we add an option to ldapsearch to allow a network
timeout to be specified on the command line.
A patch against HEAD is attached.
I am aware that you can specify NETWORK_TIMEOUT in ldap.conf, and that free
command line options are precious.